Box spring structure

ABSTRACT

A combined inner spring unit and an upholstery framing unit utilizing to the utmost the load-sustaining properties of the parts and reducing to a minimum the cost and weight of the finished box spring. A number of crossbeams of greater depth than thickness each has attached to the upper edge thereof, the bottom coils of a row of cone springs about 3 to 4 inches high or about half the overall height of the finished box spring. The large top coils of the springs may be interconnected before the crossbeams are connected. Optionally, before the ends of the crossbeams are connected, an even number of inner spring units may be interdigitated and shipped with or without the upholstery framing parts, to the upholsterer. The framing parts comprise opposed side rails arranged edgewise to produce the conventional overall height of about 7 to 8 inches. The siderails connect the ends of the crossbeams and terminate adjacent the end crossbeams. Additional frame bracing is optional. A relatively stiff turn of the springs is optional to prevent bottoming.

United States Patent [72] Inventor Daniel Krakauer 2,764,226 9/1956 Nachman, Jr. et a1. 267/100 Great Neck, N.Y. 3,337,882 8/1967 Swatt 5/239 [21] P 873582 Primary Examiner-Casmir A. Nunberg [22] F'led 1969 Attorney-Harry Jacobson [45] Patented Dec. 21,1971

[73] Assignee Kay Manufacturing Corp.

Bronklyn! ABSTRACT: A combined inner spring unit and an upholstery framing unit utilizing to the utmost the load-sustaining properties of the parts and reducing to a minimum the cost and ggfgfig gg weight of the finished box spring. A number of crossbeams of greater depth than thickness each has attached to the upper l 52| "-8. (1| /241, edge thereof, [he bottom coils fa row of cone prings about, 3

/248, 5/256, 5/35] to 4 inches high or about half the overall height of the finished [5 l I ll. Cl uA47! 23/04, box spring. The large top coils of the springs may be intercom A47c /00 nected before the crossbeams are connected. Optionally, be-

[] Field 0' Search 5/246, fm'c [he ends of the crogghgams are gonnecmd an even 345, 24 number of inner spring units may be interdigitated and 140/3 shipped with or without the upholstery framing parts, to the upholsterer. The framing parts comprise opposed side rails arranged ed ewise to roduce the conventional overall hei ht of Refuencescned about 7 ti 8 inche The siderails connect the ends o f the UNITED STATES PATENTS crossbeams and terminate adjacent the: end crossbeams. Addi- 287,120 10/1883 Grafton 5/239 tional frame bracing is optional. A relatively stiff turn of the 2,265,532 12/ 194i Levine 267/100 springs is optional to prevent bottoming.

1 a ,22 g i 5 a a g $5 W40 PATENTEU m2! um SHEET 1 [IF 2 All I VENTOR FATENTEU mm m $528,201 sum 2 BF 2 ATTORNEY BOX SPRING STRUCTURE This invention relates to box springs for bedding and par ticularly to the structural elements of such springs and the method of making the box springs.

While box spring dimensions and characteristics have not as yet been officially standardized, Federal specification No. AA-B-260d, Bedspring Box-Type, dated Apr. ll, 1967 lists the official government requirements for box springs and it is therefore advisable in order that the box spring be commercially acceptable, that certain rather rigid dimensional and conventional requirements be met. The overall height should be between 7 and 8 inches and the corners should be rounded to diameters of between 4 and 8 inches. The rounded corners are required to match those of the mattress with which a box spring is customarily used.

The dimensional requirements have heretofore been attained by the use of a wooden rectangular under frame having round corners. The flatly arranged side rails and end crossmembers of the frame have been overlapped at the corners and there fastened together as by nailing and rounded to the desired curvature by the removal of the excess corner wood. For efficient nailing, it has been necessary to use frame parts about I by 4 inches in cross section, for the reason that a lesser width than 4 inches fails to produce enough overlap for the rigid corners required to keep squareness of the frame after the corner wood has been removed. It will be understood that the wood dimensions given are but nominal and refer to undressed or unplaned rough lumber and that actual lumber sizes are substantially less than the nominal. The conventional frame just described, being of l by 4 inch lumber, is actually less than 2 inches high at the overlapped corners.

To support the rows of springs, the space within the frame has been filled with transverse crossbars of l by 2 inches or 1 by 3 inches in cross section, arranged flatwise and nailed to the upper wide faces of the side rails, similarly to the end crossmembers of the frame. The crossbars complete the frame For upholstery purposes, a l by 1 inch strip is secured to the under face of each of the end crossmembers to provide a nailing surface coplanar with the under face of the side rails.

The conventional height of the box spring being from 7 to 9 inches, and the overall height of the frame being about 2 inches, the convention springs are consequently about to 7 inches high and tend to sway materially unless substantially braced. Furthermore, while the flat arrangement of the frame and cross bars in the conventional manner permits the use of low-cost materials, as well as the required rounded comers, simple joining of the wood parts and an adequate supporting surface for the springs, the wood members are nevertheless visibly flexible when loaded and in use. They are not so connected as to utilize to the best advantage the full load-sustaining properties thereof. For economy in freight costs, the spring structure is frequently completed and shipped as an independently manufactured unit to the box spring maker for assembly to a load-bearing wood frame. The spring unit must therefore be so constructed as to resist distortion, dislocation and entanglement of the individual springs. It has consequently been customary not only to tie the top coils of the springs together but also to tie the bottom coils together by relatively expensive and heavy wires or the like. The flatwise arrangement of the relatively wide crossbars and the use of wires for the bottom coils of the springs ensures direct support by the crossbars of the wood frame, of the springs or of the connecting wires especially when the spacing between the crossbars is not precisely the same as that between the transverse rows of springs. The needed bottom wires result in a significant cost factor in materials and labor.

By arranging the crossbearns and side rails edgewise, by which is meant with the long narrow side edges thereof uppermost, and attaching the bottom coils of the transverse rows of springs directly to the cross beams, the present invention reduces the height of the required cone springs thereby stiffening them against undue sway, completely obviates the need for wires at the bottom coils of the springs, reduces substantially the widths of the wood elements, limits the stresses on the upholstery framing unit merely to compression insofar as load bearing is concerned, permits reduction of shipping costs by allowing the interdigitation of spring units when the framing side units are omitted therefrom, facilitates assembly of the springs row by row by known spring assembling machinery with substantial labor savings, and substantially reduces the present cost of making the box springs without sacrifice of strength and durability.

After the unit of connected rows of springs has been separated from the companion unit with which it has been nested, it becomes a simple matter in accordance with the present invention to secure the independent load-bearing spring unit to the upholstery framing unit and to complete the box spring by the addition of conventional padding and covering materials.

With the above understanding of present conventional structures for box springs and the conditions requiring and restricting radical changes in at least the dimensions and shapes of box springs, the various objects of the invention will become clear from the description which follows and from the drawings, in which:

FIG. l is a top plan view of a box spring, the top coil ties being omitted at certain areas and the covering and padding cut away to show two forms of top coil ties at other areas, the side rails and framing being omitted at one area to expose the load bearing unit for economy of illustration.

FIG. 2 is a vertical sectional view taken on the line 2-2 of FIG. 1.

FIG. 3 is a fragmentary top plan view of a modified form of the corner structure.

FIG. 4 is an elevational view of FIG. 3.

FIG. 5 is an elevational view of a typical cone spring wherein a tight stiffening coil is employed for shock absorbing purposes.

FIG. 6 is a fragmentary elevational view of two transverse rows of springs of the load bearing unit prior to the attachment thereof to the side rails which are shown in dash-dot lines.

FIG. 7 is a fragmentary side elevational view of a modified form of the connection of the crossbeams to the side rails.

FIG. b is a front elevational view of FIG. 7.

FIG. 9 is a view similar to FIG. 7 of a modified form of the connection between the crossheams and side rails.

FIG. 10! is a front elevational view of FIG. 9.

FIG. Ill is a fragmentary side elevational view of a further modified form of the crossbeam and side rail connection.

FIG. 12 is an enlarged fragmentary top plan view of the box spring structure showing another form of top coil tie.

FIG. 13 is a fragmentary vertical sectional view of the completed box spring as it appears resting on its supporting bed angle members showing another form of crossbeam and side rail connection.

FIGS. 114 to 16 are diagrammatic fragmentary top plan views of the load bearing parts showing the steps in assembling the same.

FIG. 17 is an elevational view of a pair of interdigitated load-bearing units as they appear prior to the compression and packaging thereof for shipment or storage.

FIG. 1b is a diagrammatic top plan view of the completed box spring structure foreshortened and showing a modified form of the upholstery framing unit.

FIG. 19 is a similar fragmentary view of the lower corner portion of FIG. 1%.

FIG. 20 is an elevational view of FIG. 11%.

In the illustrative embodiment of the invention shown in the upper right-hand corner of FIG. I and in FIG. s, the springs 21 are of the conventional single-cone-type having a relatively large top coil 22 and a relatively small bottom coil 23 adapted to rest on the narrow upper edge M of the crossbeam 25. However, the springs may take a variety of different forms as shown for example in FIGS. 5 and 12. In FIG. 5, the spring 26 has a bottom coil 27 of slightly greater diameter than the coil or spring turn 28 near the bottom coil, in those cases where it is desired that the bottom coil overhang the edge 24 of the crossbeam for fastening or other purposes. Suitable securing means such as the staples 29 fasten the bottom coils of the springs to the crossbeam in a transverse row and in the proper spaced relation to each other as indicated by FIG. as the second step in the method of making the box spring. The first step in said method as shown foreshortened in FIG. 14, is the provision of a row of springs for each crossbeam. The row of springs and the crossbeam holding the springs constitutes the primary spring element 30 in the construction of the loadbearing unit 31 of the box spring structure as shown, also foreshortened, in FIG. 16 and in a modified form at the upper left-hand comer of FIG. 1.

The crossbeam is of oblong rectangular cross section and is preferably of 1 by 2 inch lumber and arranged edgewise, by which is meant with the narrow 1 inch edge uppermost. Such position uses the crossbeam to the best advantage for economical load sustaining purposes. It also makes it possible without other aid to reduce the height of the springs 21 by 1 inch from the height required when the crossbeams are arranged flatwise. The shorter spring is obviously firmer and less expensive. In addition, as indicated by the emphasized lines of FIG. 5, one of the intermediate turns or coils 28 of the spring may optionally be made stiffer than the others, better to absorb impact or shock stresses produced as when children bounce on the box spring in play.

After a sufficient number of spring elements 30 have been assembled, they are arranged in the proper longitudinal spaced relation to each other as shown in FIG. 16 and the top coils of the rows of springs are interconnected. Three forms of such interconnections are shown herein, two in FIG. 1. At the upper left of FIG. 1, the crossed tension springs 32 are shown for the purpose mentioned and at the upper right, the long crimp wires arranged in longitudinal and transverse sets tangential to the top coils as at 33 and the links 34 connecting the midpoints of the top coils, are used to connect the springs. A heavy border wire completes the load-bearing unit.

To make it possible to assemble the spring row elements 30 by means of automatic machinery of the type now in use, as for assembling spring rows in mattresses, the top coils of the springs 35 of FIGS. 12, 14-16 and 18 are extended sufficiently to enable them to be tied by the transverse helicals 36 to the row of springs of the adjacent elements 30 as shown in FIG. 16. Where a border wire is desired as it usually is, the border wire 37 is clipped to the top coils of the marginal rows thereby completing this type of load-bearing unit. Such units are then ready for shipment if desired, to the upholsterer, or they may be stored and later framed and upholstered.

For shipment economically in a compact package or even for storage purposes, one unit 31 of a pair of such units is inverted and interdigitated with the other similar unit of the pair as shown in FIG. 17. Since the load-bearing unit at this stage is independent of the side rails, the interdigitation of the pairs of units 31 is easily accomplished without interference with any of the upholstery framing elements. For shipment, the required number of pairs of interdigitated units are compressed and tied into a package.

On separation of the individual pairs of units, each of the load-bearing units is assembled with a framing and upholstery unit which itself may be preassembled and which may take various forms. In the form shown in FIG. 1, the side rails 40 of the frame are preferably, though not necessarily, of l by 2 inch lumber and are also set edgewise, that is, with the 2 inch height vertical. The end portions of the cross beams 25 rest on and are suitably secured to the upper edges 41 of the side rails by nails, screws, glue or the like fastening means in the form of connection shown in FIG. 6. To facilitate a nailing connection, as shown in FIG. 13, the upper corner portions of the cross beams may be bevelled off as at 42, and for additional strength the corner bracing block 43 may be secured to the crossbeam and side rail.

In another form of connection shown in FIGS. 7 and 8, the crossbeam 44 is somewhat shorter and abuts the inner surface of the side rail while projecting only half way thereabove. The comer bracing block 45 aids in making a strong joint.

As shown in FIGS. 9 and 10, a lap joint 46 is used for the connection, part of the lower corner of the crossbeam 47 being cut away so that it does not project for its full height above the side rail. In all the forms of the joint however, the crossbeam projects a substantial amount, not less than half the height thereof, above the side rails to attain the objective of a spring substantially shorter than the conventional springs now in common use.

To still further shorten the springs as shown in FIG. 11, the flatwise arranged side framing member may be added to the bottom edge of the side rails. When the flat framing member 50 is 1 inch high, the springs need only be about 3 inches high. The member 50 also provides a wide horizontal surface for the attachment of the covering material and permits the crossbeams to be of substantially lesser length than the final width of the box spring.

In the framing unit, the end framing members connecting the side rails may also take various forms. As shown in FIGS. 1, 12 and 13, the preferably 1 by 1 inch end pieces 51 of the frame are shorter than the crossbeams by an amount equal to the radius of the quadrantal corner piece 52 which connects the end of the side rail to the end of the end piece 51 at each comer of the frame. In the form shown in FIGS. 18, 19 and 20, the end piece 54 is arranged flatwise and is of l by 2 inch or I by 3 inch lumber and is quadrantally curved at its ends and connected to the side rails. FIGS. 3 and 4 show the thin metallic or plastic strip 55 as the end piece of the frame. Said strip has rounded quadrantal end portions suitably secured to the side rails and need not be the full height of said rails.

To complete the box spring after the load-bearing unit has been suitably fastened to the upholstery and framing unit, conventional padding 56 (FIGS. 1, l2 and 13) and sheet covering material 57 are applied and secured to the framing unit. The use of end members and side rails to form a framing unit which is assembled to the spring structure results in an adequately strong box spring since the framing unit is subjected to an insignificant load only. The main loads are transferred by the end portions of the crossbeams as spaced-apart virtually concentrated forces applied to the side rails to subject them to compression. The side rails have no bending stresses because of the support thereof along the entire lengths by the bed angle members 53, FIG. 13, and consequently need not be considered as part of the load bearing unit.

The structure may be braced if necessary to prevent distortion. For example, any tendency to overturn the side rails or to twist or warp the box spring structure resulting from forces in unexpected directions during handling or shipment, is resisted by the optional corner braces 58 (FIG. 1). Similarly, forces tending to swing the upper edges of the crossbeams toward or from the head or foot of the structure may be resisted by the optional short longitudinal braces 59, 60 and the like extending between pairs of the crossbeams.

It will now be seen that the dimensional and shaping requirements for box springs are met by the upholstery and framing unit substantially independently of the load bearing unit with economy of material and labor and with added strength and load bearing capacity over conventional box springs and that the objects of the invention have been adequately attained.

While certain specific forms of the invention and certain dimensions have herein been shown and described, various obvious changes may be made therein without departing from the spirit of the invention defined by the appended claims.

I claim:

1. An inner spring and upholstery framing structure for a box spring or the like comprising a load-bearing unit and a framing unit comprising side rails each at least as high as the width thereof and end rails, said load-bearing unit comprising a multiplicity of crossbeams each higher than the thickness thereof and arranged transversely with the lower edges thereof resting on the upper edges of the side rails, a row of spacedapart coil springs on and upstanding from the upper edge of each of said crossbeams, the height of said row of springs and the combined heights of the crossbeams and the framing unit being approximately alike, means securing the bottom coil of each spring to the upper edge of a crossbeam, means tying together the top coils of the rows of springs, the box spring having an overall height of from 7 to 8 inches. the thicknesses of the crossbeams being not greater than 1 inch, the height of the springs being from 3 to 5 inches, and the combined height of the side rails and crossbeams being the difference between the height of the springs and the overall height of the box spring.

2. An inner spring and upholstery framing structure for a box spring comprising a load-bearing unit having a multiplicity of spaced apart springs arranged in transverse rows, transverse crossbeams arranged edgewise and secured to and spacing the bottom coils of the springs in each transverse row, and an upholstery framing unit comprising longitudinally arranged side rails secured to and spacing the end portions of the cross beams, said springs having at least one of the coils thereof stiffer than the remaining coils, said stiffer coil operating to resist impact shock and bottoming of the spring.

3. An inner spring and upholstery framing unit for a box spring comprising a load-bearing unit having a multiplicity of spaced-apart springs arranged in transverse rows, transverse crossbeams arranged edgewise and secured to and spacing the bottom coils of the springs in each transverse row,

and an upholstery framing unit comprising longitudinally arranged side rails secured to and spacing the end portions of the crossbeams, the top coils of the springs being extended sufficiently to bridge the space between the transverse rows of springs, and transverse helicals connecting the top coils of adjacent transverse rows of springs.

41. The box spring structure of claim 4, inclined corner braces between the side rails and the end rails at the head and foot of the load-bearing structure and relatively short longitudinal braces secured to and arranged between selected pairs of adjacent crossbeams and substantially coplanar therewith and transferring stresses therebetween and resisting rotation thereof about the respective axes of adjacent cross beams.

b. The box spring structure of claim 5, each of the crossbeams being reduced in height at the end parts thereof, and fastening means engaging said end parts and said side rails and securing said parts to said rails.

6. The box spring structure of claim il, the load-bearing unit being adapted for nesting in upside down position to arrange the crossbeams of each load-bearing unit between respective pairs of the top coils of the springs of the other unit thereby to form a compact storage and shipping package prior to the attachment of said unit to the side rails.

7. An inner spring and upholstery framing structure for a box spring or the like comprising a load-bearing unit and a framing unit comprising side rails each at least as high as the width thereof and and rails, said load-bearing unit comprising a multiplicity of crossbeams each higher than the thickness thereof and arranged transversely with the lower edges thereof resting on the upper edges of the side rails, a row of spacedapart coil springs on and upstanding from the upper edge of each of said crossbeams, the height of said row of springs and the combined heights of the crossbeams and the framing unit being approximately alike, means securing the bottom coil of each spring to the upper edge of a crossbeam, means tying together the top coils of the rows of springs, bevelled upper corners at the end portions of each of the crossbeams and fastening means securing said bevelled corners to the side rails.

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1. An inner spring and upholstery framing structure for a box spring or the like comprising a load-bearing unit and a framing unit comprising side rails each at least as high as the width thereof and end rails, said load-bearing unit comprising a multiplicity of crossbeams each higher than the thickness thereof and arranged transversely with the lower edges thereof resting on the upper edges of the side rails, a row of spaced-apart coil springs on and upstanding from the upper edge of each of said crossbeams, the height of said row of springs and the combined heights of the crossbeams and the framing unit being approximately alike, means securing the bottom coil of each spring to the upper edge of a crossbeam, means tying together the top coils of the rows of springs, the box spring having an overall height of from 7 to 8 inches, the thicknesses of the crossbeams being not greater than 1 inch, the height of the springs being from 3 to 5 inches, and the combined height of the side rails and crossbeams being the difference between the height of the springs and the overall height of the box spring.
 2. An inner spring and upholstery framing structure for a box spring comprising a load-bearing unit having a multiplicity of spaced apart springs arranged in transverse rows, transverse crossbeams arranged edgewise and secured to and spacing the bottom coils of the springs in each transverse row, and an upholstery framing unit comprising longitudinally arranged side rails secured to and spacing the end portions of the cross beams, said springs having at least one of the coils thereof stiffer than the remaining coils, said stiffer coil operating to resist impact shock and bottoming of the spring.
 3. An inner spring and upholstery framing unit for a box spring comprising a load-bearing unit having a multiplicity of spaced-apart springs arranged in transverse rows, transverse crossbeams arranged edgewise and secured to and spacing the bottom coils of the springs in each transverse row, and an upholstery framing unit comprising longitudinally arranged side rails secured to and spacing the end portions of the crossbeams, the top coils of the springs being extended sufficiently to bridge the space between the transverse rows of springs, and transverse helicals connecting the top coils of adjacent transverse rows of springs.
 4. The box spring structure of claim 4, inclined corner braces between the side rails and the end rails at the head and foot of the load-bearing structure and relatively short longitudinal braces secured to and arranged between selected pairs of adjacent crossbeams and substantially coplanar therewith and transferring stresses therebetween and resisting rotation thereof about the respective axes of adjacent cross beams.
 5. The box spring structure of claim 4, each of the crossbeams being reduced in height at the end parts thereof, and fastening means engaging said end parts and said side rails and securing said parts to said rails.
 6. The box spring structure of claim 4, the load-bearing unit being adapted for nesting in upside down position to arrange the crossbeams of each load-bearing unit between respective pairs of the top coils of the springs of the other unit thereby to form a compact storage and shipping package prior to the attachment of said unit to the side rails.
 7. An inner spring and upholstery framing structure for a box spring or the like comprising a load-bearing unit and a framing unit comprising side rails each at least as high as the width thereof and end rails, said load-bearing unit comprising a multiplicity of crossbeams each higher than the thickness thereof and arranged transversely with the lower edges thereof resting on the upper edges of the side rails, a row of spaced-apart coil springs on and upstanding from the upper edge of each of said crossbeams, the height of said row of springs and the combined heights of the crossbeams and the framing unit being approximately alike, means securing the bottom coil of each spring to the upper edge of a crossbeam, means tying together the top coils of the rows of springs, bevelled upper corners at the end portions of each of the crossbeams and fastening means securing said bevelled corners to the side rails. 